The exposure triangle is used to determine the exposure of the ISO, aperture and the shutter speed.

Exposure is the amount of light reaching the image sensor, this is determined by the shutter speed. exposure is measured in lux seconds.

The higher the shutter speed the less light is allowed into the sensor which allows the image to freeze.

The lower the aperture the less light is entering the sensor which causes a greater depth of field.

The more light allowed into an image can cause the image to be less detailed this is due to the ISO been too high for example if the ISO is 12800 the less detailed the image will be.